1. Field of the Invention
The present invention relates to a power transfer device associated with a power transmission for a four wheel drive vehicle to selectively transfer output drive torque of the power transmission to a pair of front road wheels and a pair of rear road wheels, and more particularly to a power transfer device capable of selectively providing a high speed two wheel drive, a high speed four wheel drive, and a low speed four wheel drive.
2. Description of the Prior Art
In a Japanese Early Publication for Patent No. 58- 211056, there has been proposed a power transfer device of this kind which comprises a change-speed mechanism capable of selectively establishing either a high speed drive power train or a low speed drive power train, and a changeover mechanism capable of selectively establishing either a two wheel drive power train or a four wheel drive power train. In such a conventional power transfer device as described above, two independent shift mechanisms are installed in a space in the transfer device to operate the change-speed mechanism and the changeover mechanism, respectively. For this reason, the transfer device may not be of a small size due to the existence of each space for the shift mechanisms.